Lubricating compositions



United States Patent LUBRICATING COMPOSITIONS Harvey M. Trowbridge and Harold A. Woods, Martinez, Califi, assignors to Shell Development Company, New York, N .Y., a corporation of Delaware No Drawing. Application August 10, 1955 Serial N0. 527,648

2 Claims. (Cl. 25237.2)

This invention relates to lubricants and more particularly to gear lubricants for use under extremely high pressure and over a Wide range of temperature conditions.

Lubricants of this type for semi-open or open gear lubrication must be viscous and they should be capable of carrying highloads at elevated temperatures. Such lubricants must have good adhesive properties so as not to be thrown olf the running gears. They must be water-resistant and they should be in a form which can be easily handled and applied.

An object of the present invention is to provide a lubricant having good high temperature and pressure properties. vide a lubricant of good adhesive properties over wide temperature conditions. Still another object of this invention is to provide a lubricant which is water-resistant and which is easy to use and apply. Other objects will become apparent from the detailed description of the invention.

It has now been found that the foregoing objects are attained by a lubricant comprising (I) a major portion of a base mixture of substantial proportions each of a mineral oil of lubricating viscosity and an asphalt obtained from such sources as asphaltic base crudes and which is predominantly aromatic in character and (II) a minor portion of the combination of minor proportions each of three essential additives, namely: (1) an oil-soluble heavy metal soap, (2) an oil-soluble polyhalohydrocarbon thiocarbamate and (3) an oil-soluble ester of a high molecular weight aliphatic carboxylic acid and a low molecular weight monohydroxy alcohol. These esters in combination with additives (1) and (2) produce a synergistic effect in that the extreme pressure properties of the total additive combination is activated and greatly increased.

The mineral oil component of the base (I) can be a liquid hydrocarbon of natural or synthetic origin and can range in viscosity from a light distillate mineral oil fraction to a heavy lubricating oil, such as gas oil, mineral lubricating oil, cylinder stock or Bright Stock or mixtures thereof. Mineral lubricating oils ranging in viscosity from 40 to 150 SSU at 210 F. are preferred.

The asphalt component of the base (I) can be obtained from various asphaltic crudes using various processes known to the art. The preferred asphaltic bitumens are those which have softening points between about 100 F. and 250 F. and preferably between 100 F. and 150 F. and which are predominantly arohaving the properties given in Table 1.

Another object of the invention is to pro One of the three essential additives incorporated in the compositions is an oil-soluble heavy metal salt or soap, of a cyclic carboxylic acid,,of an organic sulfonic acid, of a high molecular weight fatty acid and mixtures thereof, such as lead or zinc salts of cyclic carboxylic acids, such as naphthenic acid, abietic acid and other resin acids; of organic sulfonic acids, such as petroleum .sulfonic acids, and of higher fatty acids, such as oleic acid, stearic acid and the like; lead salts of cyclic carbloxylic acid, e.g., lead naphthenate represent a preferred c ass.

The naphthenic acids and their refined product can be prepared by the processes described in US. Patents 2,200,711, 2,214,438, 2,296,039 and 2,537,516. The molecular weight of the naphthenic acid can vary from as low as about 200 to as high as about 1,000, while those which have molecular weights within the range of from 350 to 600 are particularly effective for attaining the objectives of this invention.

A second essential additive is an oil-soluble halohydrocarbon thiocarbonate ester, preferably a polychloroalkyl hydrocarbon thiocarbonate, which can be represented by the formula X Rcn-Rsc,

where the Ys are S or O chalcogen atoms, at least one being a sulfur atom, the Xs are halogen atoms, preferably a middle halogen (chlorine or bromine: atomic number from 17 to 35), chlorine being particularly useful, n and m are whole numbers with their sum being at least 2, and R and R are hydrocarbon radicals containing a total of at least 12 carbon atoms, at least one of them preferably being an aliphatic hydrocarbon radical of at least 10 carbon atoms, preferably from 12 to 30 carbon atoms and having at least two substituent halogen atoms, R is preferably a long-chain aliphatic radical.

These halohydrocarbon thiocarbonate esters are suitably prepared by the reaction of polyhalohydrocarbons with less than the stoichiornetrically equivalent amount of an alkali or of an alkali earth metal organo thiocarbonate, with the formation of the alkali or alkali earth metal halide and the thiocarbonate full ester.

As already indicated, the thiocarbonate may be a mono-, dior tri-thiocarbonate. Accordingly, for the preparation of the full ester, various alkali or alkali metal organo thiocarbonates can be suitably used, such as the sodium, potassium, calciumand barium hydr0- carbon Xanthates and corresponding monoor tri-thiocarbonates. Illustrative suitable substances are alkali metal lower alkyl xanthates, such as sodium methyl xanthate, potassium methyl xanthate, potassium ethyl xanthate, potassium butyl xanthate, sodium amyl Xanthate, and potassium amyl xanthate and alkali metal cule.

f particularly those pr from 1 to 6: carbon atoms.

lower aralkyl xanthates, such as potassium benzyl xanthate. The monoand tri-thiocarbonate ester salt reactants are illustrated by the substances more simply designated by their formulae: CH O-CO'SNa,

C H CH S CO ONa, 3 and 5 corresponding other esterjsalts in nah d opar qa radicals of from 1 t 7 carbon atoms.

The thiocarbonateLester-salts are suitably reacted with various polyhaliogenated hydrocarbons in such proportions as to leave at least one halogen atom in the resulting thiocarbonate full ester. The polyhalogenated hydrocarbons are preferably polych-lorinated aliphatic hydrocarbons of from about 2 to about 30 carbon atoms per mole- Mixtures of polychloroalkanes, including cyclic and acyclic alkanes, are particularly useful, giving products which are somewhat more compatible with the other components of the composition over a wider temperature range. Polyhaloalkenes are also useful reactants. Some readily available materials which may be used are chlori- --nated naphtha, chlorinated paraflinic lubricating oil mixture of hydrocarbons, chlorinated paraffin wax and chlorinated rubber.

As indicated, the reactants are reacted in proportions such that the final product contains both chlorine and thiocarbonate groups. The amounts of chlorine and sulfur in the final product can vary over a wide range such as from about 25 to about 40% byv weight chlorine and from about 7 to about 15% sulfur.

Illustrative products of this type can be prepared as described in the following examples:

Example I One hundred parts of 'chlornaphtha (chlorinated Stoddard solvent of 49% chlorine content) was reacted with 52 parts of potassium methyl xanthate (CH-,-O-CSSK), using acetone as a solvent .and following the same general procedure described above, except that the mixture was refluxed for one hour. 7 The product obtained, designated hereinafter as .Example I additive, which we may termchlornaphtha methyl xanthate, contained 32.45% by weight chlorine and 9.79% by weight sulfur (about 14% of the characterizing xanthate group). The ratio of chlorine to sulfur being around 3 :1 respectively.

Example II Petroleum naphtha (Stoddard solvent) was chlorinated by bubbling chlorine gas therethrough until it contained about 52% 'by weight of chlorine. 225 parts by weight of the chlornaphtha was then admixed with about 400 content of about 10%, or a tri-thiocarbonate (divalent CS content of about 11.3%.

Similar polychlornaphtha alkyl xanthates are marketed by the Monsanto Chemical Company under the .name Santopoid.

A third. essential additive is an oil-soluble ester of a high molecular, weight monocarboxylic acid and a low molecular weight alcohol. Acids which can be used to form the esters include C to C fatty acids such as lauric, myristic, palmitic, stearic and oleic acids while the alcohols can be aliphatic monohydric alcohols such as methyl, ethyl, propyl, .butyl, hexyl and octyl alcohols, The esters can be illustrated'by methyl propyl, butyl or octyl The acetone was removed by 4 laurate, palmitate, stearate, oleate and mixtures thereof. Preferred esters are methyl and/or butyl stearate.

The general formulation of compositions of this invention can be represented by:

Broad Range (Percent wt.)

Limited Range (Percent wt.)

Components A composition of this invention is illustrated by the following example:

COMPOSITION A 7% Wt. lead naphthenate 6% wt. Santopoid S 1 1% Wt. butyl stearate 86% wt. of a mixture of 40% pale oil (80 SSU at 210 F.) and asphalt 1 Chlornaphtha xanthate, made by Monsanto Chemical Company and having the following properties Sp. gr. 25/151 C. w Flash, F., (3 Pour point, F. SUS vise. at 100 F Color Dark brown.

Sulfur, percent 10-15. Chlorine, percent 30-35.

Other examples of this invention include about 80 to 90% of a mixture of from 30 to 40% mineral oil and 60 to asphalt containing from about 3% to about 8% of lead rosinate, lead abietate, Zinc naphthenate and/or zinc abietate; from about 3% to about 7% additive of Example I or II or the reaction product of chlorinated petroleum naphtha and potassium ethyl xanthate 12% S, 35% C1), or the reaction product of chlorinated kerosene (40% Cl) and potassium isopropyl xanthate (10% S. 32% Cl) and mixtures thereof, and from about 0.5% to about 1.5% butyl ricinoleate, octyl palmitate and/or butyl chlorostearate.

Compositions of this invention, when tested in the Timken Lubricant Testing Machine (4 gram test procedure) described in the Lubricating Engineering, vol. 9, No. 6, 1953, page 295, indicated that they possess excellent load carrying capacity. Thus, Composition A of this invention when tested in this machine indicated excellent load carrying capacity after 480 minutes of testing. Similar results can be obtained when from about 6 to 10% lead rosinate, lead abietate, zinc naphthenate or zinc abietate is used in place of lead naphthenate, or when from about 5% to about 8% of the reaction product of chlorinated petroleum naphtha and potassium ethyl xanthate or reaction product of chlorinated kerosene and potassium isopropyl xanthate or additives of Examples I and II are used in place of Santopoid and from 1 to 2% of butyl ricinoleate, butylchlorostearate or octyl palmitate are used .in place of butyl stearate in base mixtures of mineral oil and asphalt as described in CompositionA of this invention. On the other hand when Composition 1 (6% Santopoid S and 94% of a mixture of 40% pale oil (.80 SSU at 210 F.) and 60% asphalt); Composition 2 (10% Pb naphthenate, 10% Santopoid S and 80% a mixture of 40% pale oil (80 SSU at 210 F.) and 60% asphalt); Composition 6 (7% Pb naphthenate, 6% Santopoid S, 3% W001 grease alcohol and 84% of a mixture of 40% pale oil (80 SSU at 210 F.) and 60% asphalt); Composition 7 (7% Pb naphthenate, 6% Santopoid S, 1% primary amine derived from coconut fatty acid and 86% of a mixture of 40% pale oil (80 SSU at 210 F.) and 60% asphalt); Composition 8 (7% Pb naphthenate, 6% Santopoid S, 1% polyoxyethylene difatty acid and 86% of a mixture of 40% pale oil 80 SSU at 210 F.) and 60% asphalt); Composition 9 (7 Pb naphthenate, 6% Santopoid S, 3% sodium borate and v 86% of a mixture of 40% pale oil (80 SSU at 210 F.) and 60% asphalt); and Composition 10 (7 Pb naphthenate, 6% Santopoid S, 1% treated clay and 86% of a mixture of 40% pale oil (80 SSU at 210 F.) and 60% asphalt) when tested in the Timken Machine under the same test conditions as used when testing Composition A gave times in minutes of 12, 16, 10, 28, 10, 11, 15, 11, 16 and 15, respectively, before failure resulted, indicating that compositions of this invention were from 17 to 48 times as eifective load carrying and extreme pressure lubricants than Compositions 1 through 10.

Compositions of this invention can be modified by addition thereto of minor amounts (0.011%) of antioxidants, corrosion inhibitors, extreme pressure agents, anti-wear agents and the like, such as alkyl phenols (2,6- ditertbutyl-4-methylphenol), amines, e.g., phenylnaphthylamine; organic phosphorus compounds, e.g., dilauryl 6 phosphate, dilauryl phosphite, tributyl phosphate, tricresyl phosphate; sodium nitrite, lithium nitrite, etc.

We claim as our invention:

1. A lubricating composition comprising a major proportion of (I) a base mixture of from about to about of a mineral oil and from about 70 to about 60% of asphalt and having incorporated therein (II) from about 6% to about 10% oil-soluble lead naphthenate, from about 6% to about 8% of an oil-soluble polychlornaphtha xanthate containing from about 25% to about chlorine and from about 7% to about 15% sulfur in the molecule and from about 1% to about 2% butyl stearate.

2. A lubricating composition comprising a major proportion of a base mixture consisting essentially of 40% wt. mineral oil and wt. asphalt, about 7% wt. lead naphthenate, about 6% wt. polychlornaphtha xanthate containing about 30% wt. chlorine and about 10% wt. sulfur and about 1% wt. butyl stearate.

References Cited in the file of this patent UNITED STATES PATENTS 2,210,140 Colbeth Aug. 6, 1940 2,292,672 Swenson Aug. 11, 1942 2,331,005 Story et a1. Oct. 5, 1943 2,516,119 Hersh July 25, 1950 2,607,732 Duchon et al Aug. 19, 1952 2,607,733 Oberlink et a1 Aug. 19, 1952 2,785,130 Langer Mar. 12, 1957 

1. A LUBRICATING COMPOSITION COMPRISING A MAJOR PROPORTION OF (1) A BASE MIXTURE OF FROM ABOUT 30 TO ABOUT 40%OF A MINALERAL OIL AND FROM ABOUT 70TO ABOUT 60% OF ASPHALT AND HAVINF INCORPORATED THEREIN (11)FROM ABOUT 6%TO ABOUT 10%OIL SOLUBLE LEAD NAPTHENATE, FROM AOUT 6% TO ABOUT 8% OF AN OIL -SOLUBLE POLYCHLORNAPHTHA XANTHATE CONTAINING FROM ABOUT 25% TO ABOUT 45% CHLORINE AND FROM ABOUT 7% TO ABOUT 15% SULFUR IN THE MOLECULE AND FROM ABOUT 1% TO ABOUT 2% BUTYL STEARATE. 